You can do this via 'Settings' > 'Favourites'. Choose '+' to add a Favourite Individual, Biller or Top Up.
You can also add a Favourite when paying a recipient by toggling on 'Add to Favourites' after you've filled in the recipient details.
While you're adding your Favourites, you can also set them as a Quick Link which pins them to your Home screen.
Quick Links are eligible for Quick Pay, an additional feature that lets you make payment after you've logged into the RHB Mobile Banking App.